Centrifugal machine for filtering purposes



y 1937. G. E. NELIN 2,087,778

CENTRIFUGAL MACHINE FOR FILTERING PURPOSES Filed Feb. 4, 1956 Fig.1.

. INVENTOR Gustav Ezwk JVLL'n BY M M ATTORNEYS UNITED STATES PATENTOFFICE CENT'RIFUGAL MACHINE FOR FILTERING PURPOSES Gustav Erik Nelin,Helsingfors, Finland, assignor to Kone ja Silta 0. Y. Maskin och Bro A.B., Helsingfors, Finland Application February 4, 1936, Serial No. 62,299

In Finland January 7, 1936 4 Claims. (01; 210-64) The increased claimswith regard to high cathe holes 4 and 4 adjustable by the screws 3 andpacities have brought about that centrifugal ma- 3 or through theopening 2 out of the bowl. chines for filtering purposes have in certainin- In Figs. 2, 3 and 4 different arrangements of dustries more and morereplaced the old filterfiltering structures are presented. In Fig. 2 a

5 ing methods in which the force which is necesfiltering body 5 isarranged in various apertures 5 sary in order to overcome thecounter-pressure and a layer of cloth 6 is arranged on the outof thefilter is obtained by the own weight of the side of the wall, namely theside from which fluid or by pressure-pumps. Ahead of same, centhe liquidflows. In Fig. 3 a reverse arrangetrifugal machines oifer the advantagethat the ment is provided, namely the filtering medium 5 10 pressure,influencing the capacity so essentially, is arranged in a similar mannerto that shown 10 can be easily increased in these machines to a in Fig.2 but the cloth 6 is arranged interiorly nearly arbitrary degree.However, also in other of the wall. In Fig. 4 a still further modifiedrespects the centrifugal machines are superior arrangement is shownwherein a layer of cloth to the former, because fluids of diiferentspecific is arranged on both sides of the wall. 7

weight can be separated from each other, which If the separated fluid ispermitted to leave the 15 cannot be effected by the other method. It isbowl after having passed through the filter cloth also possible tounburden the filter from the most 6, the result is not perfectly good,particularly if coarse-grained impurities by constructing special it hasbeen necessary to use a filter which is slime spaces where thecoarse-grained particles, not very tight so as to obtain a tolerably bigbeing heavier than the fluid, deposit. capacity, even with fluids ofhigh viscosity. The 20 Thedisadvantage connected with the operationsidea of the invention described above consists is the fact that theeffective surface of the filter therein that the fluid subject topurification has cannot be made sufliciently big so as touse fine alsoto pass through a powder filter which most filters at high capacities.In has, therefore, been suitably is eiTected by putting a powder ofhigher necessary to reduce the claim onpurity. specific weight,--mixedup with the fluid-into 25 In the present invention this disadvantage hasspace 8 where same is separated when the bowl is been remedied in suchaway that an extra clearrotating and is deposited on the interior of thefiltering is effected by means of a powder-filter wall ill, whereby alsothe holes 5 are filled up. with more or less graniform particles. Withinthe powder the fluid is now subject to a In the accompanying drawing-Close purification, which does not only consist of 30 Figure l is alongitudinal vertical sectional View the filtration effect createdbetween the particles through a centrifugal machine disclosing an emofthe mass and known from ordinary pressure bodiment of the invention; 7filters, but even is caused. by a separation of an- Fig. 2 is afragmentary sectional View through other kind, taking place within themass. On

one of the walls illustrated in Fig. 1 and showaccount of the adhesionto the particularly wide 35 ing the arrangement of filtering powder inthe total surface of the powder-mass, created by its openings in thewall, the same forming certain being s fi e fluid s fO ced, even atfeatures of the invention; great speeds, to pass in a laminated waythrough Fig. 3 is a view similar to Fig. 2 but showing a the powd r- Dus l mina p n he modified construction, and centrifugal power effects 'aseparation like the 40 Fig. 4 is a view similar to Fig. 2 but showing aone which takes place within ordinary bowls second modifiedconstruction. equipped with insertion plates. The heavier par- Throughthe pipe I the fluid which is to be ticles are forced to move outwards ashort way separated enters into the bowl. In the foren rad al directiOnuntil t y Stick On to t e slimespace 9 the coarsest impurities depositbesurface of some grain. 45

cause, on account of their high specific weight, This process is mostimportant ec e n the same are forced by the centrifugal power tomajorityof fluids there is mixed up ingalmost wards the periphery. Thefore-slimespace 9 comcolloidal state some other fluid of heavierspecific municates by the channel .H with the exterior weight (e. g.water in olive oil) which then, even slimespace l where, owing to theincreased cenin extremely small quantities can greatly change 5 trifugalpower, the fluid is subject to a closer the appearance of the mass.These impurities purification. From the slimespace I the fluid is mixedup with the fluid cannot be separated by pressed through the filter6,which is stretched means of an ordinary filter, but certainly by a cuton the exterior of the wall If], perforated by powder filter throughwhich under the influence the holes 5,to the space 8 and thence throughi of the centrifugal power the fluid, which is to be 55,

separated, is passing. When separating certain fiuids it is of advantageto insert a powder which chemically reacts as e. g. at the extraction ofcolor from some lacquers.

It is certainly possible to carry out the above described idea incountless forms of constructions, all of which, of course, cannot bementioned within the limited space of this description. 7

In order to be able to reduce the outlet speed and at the same time alsothe energy used for separation with such powders and such capacitieswhich do not require the maximum of the fluidpressure which is at hand,the holes 4 and 4 are arranged at dilferent distances from the centre,which holes can be opened and closed by means of the screws 3 and 3 Iclaim:

1. A centrifugal filtering machine including a casing, means within thecasing forming a chamber provided with a bottom having an outlet, a

solid inner wall upstanding from said bottom, an outer foraminous wallupstanding from said bottom, said foraminous wall being spaced from saidcasing and said inner wall and acting as an inlet to the space' be'tweensaid inner and outer walls, said outlet from the bottom of the bowlbeing in free communication with the space between the casing and theforaminous wall, a filtering powder arranged in each of the openings insaid foraminous wall, and a sheet of filtering cloth positioned on eachside of said wall so that the liquid passing through said foraminouswall must first pass through one filtering cloth, then through thefiltering powder, and finally through the second filtering cloth.

2. A centrifugal filtering machine comprising a casing, a bowl arrangedwithin said casing, said bowl being formed with an inner chamber havingan inlet at the top and an outlet at the bottom, said bowl being alsoprovided with an outer chamber surrounding said inner chamber, theenclosing wall of said inner chamber being solid throughout and formingthe inner wall of said outer chamber, said outer chamber being formedwith a foraminous outer wall connected at its lower edge with the loweredge of said enclosing wall, said bowl being spaced from said casingexcept at the upper end with the space between the casing and the outerwall of the bowl being in free communication with said outlet, and afiltering member positioned in each of the openings in said outer wall,said outer wall being positioned so that all liquid flowing through saidouter wall into said outer chamber must flow through the filteringmembers.

3. A centrifugal filtering machine comprising a liquid tight casinghaving a displacement member extending upwardly from the bottomcentrally thereof, a cover member for said casing formed with liquiddischarge openings, a bowl arranged in said casing positioned out ofcontact therewith except at the top portion of said displacement memberand the top peripheral edge of the casing, said cover member acting toclamp said bowl to said peripheral edge, said bowl being formed with aninlet at the top and a bottom H spaced from the bottom of the casing andhaving an opening around said displacement member, and a pair of spacedupstanding walls adjacent the periphery of the bottom, the outer of saidupstanding walls being spaced from said casing and formed with openingstherein, and a filtering material positioned in each of said openingswith the space between said upstanding walls being in free communicationwith said liquid discharge openings in said cover.

4. A centrifugal filtering machine including a liquid tight casing, acover for said casing having liquid discharge openings, a bowl arrangedin said casing and formed with an inlet at the top and a bottom spacedfrom the bottom of the casing, the bottom of the bowl having a centrallypositioned opening and a pair of upstanding walls adjacent the peripheryof the bottom, the inner of said upstanding walls being solid throughoutwhile the outer of said upstanding walls is spaced from said casing andformed with apertures therein, and a filtering material positioned ineach of said apertures with the space between said upstanding wallsbeing in free communication with said liquid discharge openings in saidcover.

GUSTAV ERIK NELIN.

